Recently, an image obtaining technologies using cameras have been extensively applied to various fields. For example, for driver's convenience, cameras are installed in vehicles for various purposes and development of related technologies has been explosively increased. However, with respect to some functions, if a camera does not normally operate, safety may be severely affected, and thus, in this case, the camera may not be used without a solution related thereto.
For example, in the case of around view monitoring (AVM), a camera used as a substitute for a side mirror, a fault of a function thereof may directly relate to life of a driver of a corresponding vehicle or a pedestrian, so stability of operation needs to be secured.
Also, a vehicle camera may be frequently exposed to very bright lighting such as light of the sun, a headlamp, and the like, in terms of characteristics thereof. In this situation, in the related art, sensitivity of a sensor is lowered to obtain a dark image such that other parts than lighting is impossible to recognize. Thus, a technique for improving an image in this situation is required.